Process of making camphor.



avert-ans IQSEF HER'IKORN, OF BERLIN, GERMANY.

PROCESS OF MAKING CAMPHOR.

Specification of Letters Patent.

Patented Oct. 20, 1908.

Application filed June 1, 190a. Serial No. 435,888.-

To all whom it may concern:

Be it known that I, J OSEF HERTKORN, doctorof philosophy, chemist, and resident of Berlin, Germany, whose post-oflice address is Paulstra'sse 8, have invented a new and useful Improved Process of Making Camphor, of which the following is a specification.

My invention relates to a process for making camphor from'-- borneol, isoborneol, -or their esters, or a mixture of any of them 'with camphenes. This is accomplished by sub jecting any or all of these materials to the action of nascent oxygen produced from an aqueous hy ochlorite solution.

It is well nown that camphor may be produoedby the oxidation of the borneols, but the processes for doing this are in the main unsatisfactory. For example, the treatment of the borneols with free chlorin or with aqueous hypochlorite solutions, either with or without the addition of catalytic substances, are not satisfactory, because these rocesses also result in the. production of arge quantities of lay-products and products of decomposition containing chlorin, which renders the'c omplete separation of the cam phor troublesome and even impossible from an economic standpoint. Moreover, the camphenes which are formed in considerable quantities in the direct processes for produc ing the borneol ethereal salts from oil of turpentine are entirely lost in the process recited above. Furthermore, the oxidation of the borneols with atmospheric oxygen under the action of heat, either with or without the resence of catalytic substances, is unsatisactory, because the production ofcamphor is very small, far less than the theoretically 1 possible yield, and this method is likewise objectionable in that it )roduces considerable quantities of by-pro nets and products of decomposition which in the furth r t vab ment do not yield eamphor.

My rocess, which is based on the forumtion 0 nascent oxygen in an alkaline, or ncuj tral, or slightly acid solution, which oxygen oxidizes'the borneols and at the same time the camphenes, if any are present, gives an approximately theoretical yield of cainphor without the formation of any appreciable quantity of by-products and products oi decomposition, as high as 96% of the theoretically possible yield being obtained.

The nascent oxygen is formed by treat in;

[ any aqueous hypochlorite solution with a 1 solut on, tlu'is causing a waste ol' ox gen.

mixture of the salts of the metals, (including the oxide or hydrates) of the sulfid of hydrogen and sulfid of ammonium groups, such, for example, as the compounds of copper, lead, bismuth, antimony and the like mixed with the compounds of iron, nn'ingauranium,-molybdenum, tungsten, did ymium and the like. H

As is well known, hypi'ic hlorite solutions that are not too dilute are readily decomposed even at ordinary temperatures with the formation of nascent oxygen by a mix ture of copper and iron salts, or copper and manganese salts, whereas each such salts, if used singly, do not possess this property.

For the complete decomposition of the hypochlorite solution, about 0.3 to one per cent. of the metallic salts of the sulfid of hydrogen group, mixed with from 1.5 to three per cent. of 'the salts of the sulfid of ammonium group, is used.

The cheapest hypochlorite is the chlorid of lime of commerce or the dilute hypochlorite or bleaching lyes produced electrolytically by the decomposition of the alkaline chlorids, such as rock salt.

made into a cream with from 600 to 1000 liters of water. This, or a corresponding quantity of hypochlorite of sodium lye or the like, is mixed with about two kilos of sulfate of copper or chlorid of copper and about 6 kilos of sulfate or chlorid of iron or manganese, as a saturated solution.

! The mixture is sli htly heated to start the E reaction, after which the reaction proceeds by itself and sets free oxygen. When the production of oxygen begins, 25 to 27 kilos 1 ol' borncol, or isoborneol, or camphene, or a 1 mixture of these substances or their etheral salts, are added to the liquid, the whole being constantly stirred. The borneol or similar substance may be added directly or it may be dissolved in benzin or benzol and.the so-v lution added. These substances are mixed and constantly stirred until the hypocl'iloritc is completely dcconniiosed. it the generated by the chei'nical reaction. goes too .1 high, that is, above 25 C., it may be reduced. I either by diluting the solution with water or cooling the vessel containing the solution. If the heat is allowed to rise above 25 C. the ;ev lntion ol oxygen. will be so rapid. that. bubbles of free oxygen will rise throu 'h the nese, zinc, cobalt,nickel, vanadium, titanium,

Example: 40 kilos of chlorid of lime are heat The temperature should be kept low enough to prevent the formation of bubbles and should never be allowed to rise above 25C. The product is then treated with steam, which separates the camphorbenzin or camphor-benzol solution from the oxidizing liquid, and is then further treated in the usual Way to convert it into solid camphor. The-camphor obtained by this means is snow-White and equivalent in all respects to natprgl camphor. It has a melting point of 175 If the entire uantities of material recited above are mixe together at once, the chem-,

ical action, as soon as it begins, is quite violent and the formation of oxygen may be delayed by cooling the vessel, by diluting the liquid ,With water, by adding the solution of the metallic salts bydegrees to the hypochlorite solution (which may be a concentrated solution), or by adding the energized hypochlorite solution by degrees to the borneol solution.

The mixture of metallic hydrates deposited from the oxidizing liquid may be used over and over again for further oxidizing purposes as often as desired, especially when chlorids are used.

I claim?- 1. The process of producing camphor b subjecting borneol to nascent oxygen, which which consists in adding to a solution of hypochlorite. of lime a mixture containing chlorid of iron and chlorid of copper in solution and slowly stirring borneol into the resulting product, substantially as described. 3. The process of producing camphor which consists in adding to a strong solution of hyochlorite of lime a strong solution containing chlorid of copper and chlorid of iron, adding borneol tothe resulting mixture, controlling the temperature during the oxidation of the borneol by said resulting mixture, and purifying the oxidized product, substantially as described.

In testimony, that I claim the foregoing as my invention, I have signed my name in presence of two u'tnesses, this 19th day of May 1908.

' JOSEF HERTKORN; Witnesses g WOLDEMAR HAUPT, HENRY HAsPEn." 

